The present invention relates to a color display device, and more particularly to an improvement of the color display device of a non-light-emitting type typically comprising a combination of a matrix liquid crystal display and a filter of three primary colors.
The non-light-emitting type display such as a liquid crystal display or an electrochromic display (EC) has advantages in that the displayed pattern can be seen in strong light better than a light-emitting type display such as a cathode-ray tube (CRT), as well as having low power consumption and a smaller capacity. In recent years, studies of color display devices with the non-light-emitting displays have been extensively made, and various methods have been proposed. A color display employed with a filter is disclosed in U.S. Pat. No. 3,840,695. In this method, filters of three primary colors comprising red, green and blue are disposed on corresponding display elements (picture elements). The light transmitting filter is colored depending on the color of the filter. If the pitch between color elements of three primary colors is sufficiently small, it is possible to produce a desirable color by mixing the colors.
However, in the conventional display, picture elements of three primary colors are almost equal in area and number. Therefore, in order to establish a color display having the same resolution as a monochrome display, it is necessary to increase the number of picture elements by three times as many as that of the monochrome display. The increase of the number of picture elements causes complications in the manufacturing process, driving electrodes and circuit, which results in increase of cost and size of the device.